Centrifugal pump



Dec. 31, 1963 H. HORNSCHUCH CENTRIFUGAL PUMP Filed Jan. 31, 1961 INVENTOR HAN/V5 HORIVSCHUUH mm HIS ATTORNEY United States Patent Filed Jan. 31, 1961, Ser. No. 86,067 2 Claims. (Cl. 103103) This invention relates to centrifugal pumps and particularly to a form of centrifugal pump fabricated, as to its casing, of sheet material.

The invention has for its object a form of pump casing which may be produced economically and which is suitable for direct mounting on a driving motor and the like.

Other objects of the invention will be in part obvious and in part pointed out in the following description taken with the accompanying drawing of which:

FIGURE 1 is a side view of a pump connected to a motor, the pump being in central longitudinal section,

FIG. 2 shows the pump of FIG. 1 disconnected from the motor,

FIGS. 3, 5, 6 and 7 illustrate, in sectional view, various arrangements of fitting together various portions of the pump, and

FIG. 4 shows in particular a sectional view of a preferred sealing arrangement for the pump shaft.

Referring to the drawings and particularly to FIGS. 1 and 2 there is illustrated a centrifugal pump which is adapted to be operated by a motor 10, in this case electric, having a drive shaft 12 extending therefrom. On the end of shaft 12 is mounted an impeller 14 keyed thereto as shown in FIGS. 1 and 7.

Impeller 14 is of the type known in the art as an open impeller, not being provided with shrouds. Impeller 14, see FIGS. 1 and 2, may be molded or cast of any suitable material either metal or plastic and for the purpose of strength the spirally formed blades 16 are supported on the central hub 18 by means of a rearward web (not shown).

The enclosing casing for impeller or rotor 14 consists of a front half 22 and la rearward half 24. These casing halves may be of any suitable material preferably pressed from sheets to the conformation as shown in FIGS. 1, 4, 6 and 7. The casing front half 22 has a radially extending substantially flat portion 26 adapted to fit closely with blades 16 of rotor 14, and flares at the center as at 28 to form a tubular opening 30 adapted to receive a threaded inlet nozzle 32 suitably attached permanently to the flare portion 28. Toward its periphery, casing front half 22 is provided with a bulging peripheral part 34 terminating in an axially directed lip 36. The bulging portion 34 forms part of the chamber into which the impeller blades 16 discharge the liquid being pumped, and it may be of uniform section for a greater part of its peripheral length or in the form of a volute, but is provided in either case with a tangentially directed semitubular shaped portion 38 which is the discharge portion, or half of it, fitted at its outer end with a suitable connection 42.

The back or rearward half 24 of the casing is complementary to the front half 22 and preferably is likewise formed of sheet material pressed or otherwise formed to provide a back relatively straight wall 44 slightly dished at the center as at 46 and bulging toward the periphery as at 48 to form with the bulge 34 the chamber to receive fluid projected by blades 16. At the periphery of casing half 24 is provided an outwardly extending lip 50, see FIG. 3, fitting snugly within lip 36 of casing half 26 to provide 'a seal therewith.

At the center of casing half 24 is provided a tubular portion 52 which may be pressed out of the sheet ma- 3,115,843 Patented Dec. 31, 1963 terial of casing half 24 or suitably integrally attached thereto at the center, and which provides an enclosure for a shaft seal 53 on motor shaft 12.

The construction of seal 53 is most clearly indicated in FIG. 7 and includes a stationary ring 54 provided with a scaling O-ring 56 to prevent leakage along the inner Wall of tube 52. Inner face of ring 54 is ground smooth to provide a sealing surface with a rotatable ring 58 longitudinally mounted on shaft 12 and sealed therewith by flexible packing 60 on which ring 58 may slide. Ring 58 is resiliently pressed against stationary ring 54 by means of a coil spring 62 bearing against the rear face of rotor 14. The seal 53 is held in place by means of a retainer ring 64 having cars 66 which are adapted to slide into and out of a bayonet type slot 68 in a commonly known manner.

The casing formed by the front and rear casing halves 26 and 24 are held in position by a distance piece 72 which in this case is a cylindrical sheet metal tube like member fitting the face of motor 11) and bolted thereto by means of cap screws 74 arranged at intervals peripherally. The forward edge 76 of distance piece 72 (see FIG. 3) cooperates with lip 36 of casing half 26 and with lip 50 of casing half 24 to form with the two casing portions 24 and 26 a unitary construction which is welded at the point at which they abut by welding if formed of metal, or by other suitable attaching methods if parts are to be made of plastic.

At the bottom of distance piece 72 is provided an aperture 78 which is a vent for air circulation from motor 10 as well as for leakage if any passes the seal within tube 52. To prevent creeping of liquid longitudinally of shaft 12, a flinger 80 is provided on shaft 12.

Rotor 14 is held on shaft 12 by means of a keeper ring 82 of a commonly known type fitting into a suitable slot in shaft 12 and providing an easy means of attachment or removal of rotor 14 from shaft 12, so that upon removal of cap screws 74 and keeper ring 82 the pump assembly may be withdrawn from shaft 12 for replacement.

The construction above described forms a very easily manufactured pump especially with regard to the casing. The casing parts as here shown are intended to be permanently attached together, casing halves 24, 26 and distance piece 72 having, respectively, lips iii, 36 and edge 76 fastened together as hereinbefore described. Whenever either the rotor or the casing is to be replaced, although the rotor is usually worn out about as soon as the casing, it appears to be desirable to replace both members as a unit. Even though the rotor is preferably permanently enclosed within the casing, the rotor and the casing as :a unit can be cheaply manufactured.

FIG. 2 illustrates the pump disconnected from motor 10 indicating the simplicity of removing the pump from motor 10. By disconnecting screws 74 from motor 11 and keeper ring 82 from shaft 12 the pump unit (including seal 53 and ring 64) is permitted to be removed from shaft 12 and motor 10. When installing a replacement unit, seal 53 of the unit to be replaced is removed from within tubular portion 52 after rotating cars 66 of retainer ring 64 out of bayonet slot 68 which permits removal of seal 53. The seal components are inspected and if still in good operable condition it is installed in tubular portion '52 of the new pump unit whereupon the pump unit, including seal, is connected to shaft 12 (impeller is keyed to shaft 12), keeper ring 82 snapped into place, distance piece 72 screwed to motor 10, and the pump is ready to operate.

*FIG. 4 shows a pump construction in which the casing halves 24" and 26" and distance piece 72 are slightly modified, only the peripheral lips 51) of casing halves 24" and 26" attached to each other, see FIG. 5, while distance piece 72 is attached to the straight outer Wall portion of easing half 24". The structure, as compared to that shown in FIG. 1, is further modified in that there'is provided a wall member 84 to further protect motor 18 from possible leakage along shaft '12 past seal '53 in the direction of motor 18.

In PEG. 6 is indicated a construction in which the casing halves 24 and 26' are slightly modified to accommodate a shrouded impeller 14'.

FIG. 7 shows still another pump construction in which the ends of the bulging peripheral par-ts 34 and 48 of the casing halves, and distance piece 72 are attached to each other in the manner shown.

Thus, by the above constructions are accomplished, among others, the objects hereinbefore referred to.

I claim:

1. A centrifugal pump unit adapted to be mounted on a motor including a housing containing a rotary drive shaft, said unit comprising: an impeller adapted'to be detachably fixed on the drive shaft; a centrifugal pump casing surrounding and substantially enclosing said impeller and comprising complementary front and rear casing halves which are welded together along their peripheral edges to form a permanently attached together casing enclosing said impeller; said casing including .a discharge outlet formed by complementary engaging portions of both said front and rear casing halves; said rear half of said casing including a tubular rearwiardly extending portion adapted to surround the motor shaft; a shaft seal contained within said tubular portion and fastened therein by a retainer ring having ears fitting in bayonet slots provided in said tubular portion; an annular distance piece Welded to said casing and having an open end adapted to be telescopically received over the end pontion of the motor housing adjacent the drive shaft; and means for fastening said distance piece to the motor housing to support said distance piece and said casing on the motor housing, whereby the combination pump casing and impeller unit can be removed as a. unit from the motor, when it is Worn out, and replaced with a similar combination casing and impeller unit.

2. The pump unit of claim 1 wherein: said casing and said distance piece include interengaging overlapping peripheral flanges which are welded together.

References Cited in the file of this-patent UNITED STATES PATENTS" 1,602,009 Germeyer Oct. 5, 1926 1,941,527 Aske Jan. 2, 1934 2,486,731 Buchi Nov. 1, 1949 2,745,351 Zozulin May 15, 1956 2,784,673 Narnur Mar. 12, 1957 2,844,100 Heinicke July 22, 1958 2,898,861 Wakeman Aug. 11, 1959 2,997,958 Heinicke Aug. 29, 1961 FOREIGN PATENTS 1,194,384 France May 4', 1959 651,299 Great Britain Mar. 14, 1951 716,342 Great Britain Oct. 6, 1954 251,497 Switzerland Aug. 2, 1948 

1. A CENTRIFUGAL PUMP UNIT ADAPTED TO BE MOUNTED ON A MOTOR INCLUDING A HOUSING CONTAINING A ROTARY DRIVE SHAFT, SAID UNIT COMPRISING: AN IMPELLER ADAPTED TO BE DETACHABLY FIXED ON THE DRIVE SHAFT; A CENTRIFUGAL PUMP CASING SURROUNDING AND SUBSTANTIALLY ENCLOSING SAID IMPELLER AND COMPRISING COMPLEMENTARY FRONT AND REAR CASING HALVES WHICH ARE WELDED TOGETHER ALONG THEIR PERIPHERAL EDGES TO FORM A PERMANENTLY ATTACHED TOGETHER CASING ENCLOSING SAID IMPELLER; SAID CASING INCLUDING A DISCHARGE OUTLET FORMED BY COMPLEMENTARY ENGAGING PORTIONS OF BOTH SAID FRONT AND REAR CASING HALVES; SAID REAR HALF OF SAID CASING INCLUDING A TUBULAR REARWARDLY EXTENDING PORTION ADAPTED TO SURROUND THE MOTOR SHAFT; A SHAFT SEAL CONTAINED WITHIN SAID TUBULAR PORTION AND FASTENED THEREIN BY A RETAINER RING HAVING EARS FITTING IN BAYONET SLOTS PROVIDED IN SAID TUBULAR PORTION; AN ANNULAR DISTANCE PIECE WELDED TO SAID CASING AND HAVING AN OPEN END ADAPTED TO BE TELESCOPICALLY RECEIVED OVER THE END PORTION OF THE MOTOR HOUSING ADJACENT THE DRIVE SHAFT; AND MEANS FOR FASTENING SAID DISTANCE PIECE TO THE MOTOR HOUSING TO SUPPORT SAID DISTANCE PIECE AND SAID CASING ON THE MOTOR HOUSING, WHEREBY THE COMBINATION PUMP CASING AND IMPELLER UNIT CAN BE REMOVED AS A UNIT FROM THE MOTOR, WHEN IT IS WORN OUT, AND REPLACED WITH A SIMILAR COMBINATION CASING AND IMPELLER UNIT. 